Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .Ki-67 is a nonhistone nuclear protein involved in the early steps of polymerase I-dependent ribosomal RNA synthesis and DNA replication expressed in active cell cycles. The expression of Ki-67 strongly correlates with the intensity of cell proliferation and tumour grade. In routine hematopathology, the Ki-67 index is an important parameter to classify low and high malignant lymphomas. Additionally, the Ki-67 index is a well-known prognostic marker correlating with the biological behaviour of tumours such as breast carcinoma and neuroendocrine tumours. Ki-67 index of nearly 100%, can be used as a diagnostic clue; most representative examples are small cell lung carcinoma, Burkitt lymphoma, and plasmablastic lymphoma.